BIOL 1117 Lecture Notes - Myocyte, Rigor Mortis, Relaxed Muscle

• School: Northeastern University
• Department: Biology
• Course: BIOL 1117
• Professor: Christopher Richardson

Document Summary

L19-muscle cells: the muscle fibers develop tension and may shorten, myosin atpase enzyme in myosin head hydrolyzes an atp molecule (10, energy released, activates the head cocking it into an extended position (10) This activation is endergonic: activated myosin head binds to actin active site forming a myosin - actin cross-bridge (11, contraction (steps 12, myosin head releases pi, which releases energy (12) Head shifts from unstable, high energy extend out position to low energy, bent position (exergonic: contraction (step 13) repeated (13, myosin binds to new atp and then myosin releases actin and process is. By hydrolyzing the atp and recocking or extending the heat again (recovery stroke) attach to a new active site farther down each stroke utilizes one molecule of atp. Myosin filaments crumple against z discs: if too stretched at rest, a weak contraction results little overlap between thin and thick filaments.